title: Normal values of quantitative T2' in a spontaneously hypertensive stroke prone rat stem at 3T.
abstract: BACKGROUND
  Regarding therapy and prognosis of acute ischemic stroke the identification of ischemic penumbra is pivotal. A promising candidate is BOLD-imaging using qT2'-maps. For valid interpretation of experimental studies in animals normal values for qT2' are needed. Normal values in humans at 1.5T already exist. Normal values for cortical and subcortical structures in a spontaneously hypertensive stroke prone rat stem (SHR-SP) at a fieldstrength of 3T are reported.
  
  
  METHODS
  39 (20 males and 19 females) spontaneously hypertensive stroke prone (SHRSP) rats were examined in a 3T scanner using a dedicated small animal coil. Mean weight was 144.1 ± 8.2g and mean age was 60.2 ± 2.7 days. For the calculation of qT2' multiple echo T2w and T2 w images were acquired. ROIs were placed into deep and cortical grey matter in five different brain regions to obtain values for qT2', qT2 and qT2.
  
  
  RESULTS
  Mean qT2' for cortical grey matter was 74.76 ± 33.27 ms and 67.73 ± 17.86 ms for deep grey matter. The 99% confidence interval for cortical grey matter was 69.91-79.61 ms. For qT2 it was 79.02 ± 2.9 ms and 70.45 ± 1.89 ms, respectively. For qT2 it was 34.65 ± 5.25 ms and 31.9 ± 2.9 ms.
  
  
  CONCLUSIONS
  The values for qT2' presented here can serve as reference values for further studies examining the ischemic penumbra in a rat model.
authors.affiliation: Institute of Neuroradiology, University of Schleswig-Hostein, Campus Kiel, Arnold-Heller-Str. 3, Haus 41, Germany. urj20@wbic.cam.ac.uk
authors.forename: U
authors.initials: U
authors.lastname: Jensen-Kondering
authors.forename: R
authors.initials: R
authors.lastname: Böhm
authors.forename: J
authors.initials: J
authors.lastname: Höcker
authors.forename: R
authors.initials: R
authors.lastname: Ruhe
authors.forename: J
authors.initials: J
authors.lastname: Brdon
authors.forename: S
authors.initials: S
authors.lastname: Ulmer
authors.forename: T
authors.initials: T
authors.lastname: Herdegen
authors.forename: O
authors.initials: O
authors.lastname: Jansen
mesh_terms: D000818:Animals; D002545:Brain Ischemia / Q000473:pathology*; D005260:Female; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D051381:Rats; D011918:Rats, Inbred SHR; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity